Torque transmission mechanisms for starter motors of internal combustion engines generally comprise a ring gear to which a starting torque is transmitted by a starter motor, and which transmits a torque to a one-way clutch of the torque transmission mechanism.
It is known, for example from WO-A-2007/148228, to provide a ring gear divided, along a radial direction, in three regions including a gear side region, an intermediate region and a race side region. The gear side region meshes with a pinion of the starter motor, while the race side region transmits torque to the one-way clutch.
The three regions are generally welded together using, for example, laser welding or electro beam welding. Such techniques are expensive and complex to implement. Moreover, these techniques need metallic materials of specific properties to be present on the areas which are to be welded. This implies complex manufacturing operations and is also not standard for SKF channel.
The welding process generates a dimensional modification and in consequence no control of bearing clearance.